Green Turtle Lake
Green Turtle Lake in Passaic County, New Jersey has a water quality grade of D (Nutrient-rich). Water clarity: 7.2 ft visibility. Phosphorus: 13.9 µg/L. Chlorophyll-a (algae): 16.1 µg/L. Surface area: 28 acres.
- Clarity
- 7.2 ft
- Area
- 28 acres
- Type
- Eutrophic
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Green Turtle Lake →
Green Turtle Lake is a 28-acre productive, nutrient-rich eutrophic lake in Passaic County, New Jersey. Water quality is graded D based on 2 sampling years through 2024. Compared to the 5 other monitored lakes in Passaic County, Green Turtle Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2024-07-31. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Moderate clarity, visible to about 7.2 ft. Phosphorus level: 13.9 µg/L. Chlorophyll-a: 16.1 µg/L. Trophic State Index: 50.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.2 ft | Not graded |
| Phosphorus | 13.9 µg/L | Good |
| Chlorophyll-a (Algae) | 16.1 µg/L | Poor |
| Trophic State Index (TSI) | 50 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Green Turtle Lake
Compare lakeside cabins, hotels, and vacation rentals near Green Turtle Lake in Passaic County, New Jersey — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Green Turtle Lake are listed below.
Top-rated places to stay near Green Turtle Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 28 acres |
No bathymetric survey has been published for Green Turtle Lake, so its depth is not documented here.
Fishing Green Turtle Lake
Reservoir Info (USACE NID)
Green Turtle Lake is a man-made reservoir impounded by the Green Turtle Pond Dam, built primarily for recreation on the Wanaque River-TR; earth-type dam, 35 ft tall and 305 ft long.
- Surface area
- 28 ac
- Normal storage
- 251 ac-ft
- Drainage area
- 0.5 sq mi
- Hazard class
- High
- Owner
- Division of Parks and Forestry
Source: USACE National Inventory of Dams, NID ID NJ00190 · Operator website
EPA Impairment Status
Green Turtle Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NJ02030103070030-01 · Official waterbody report · Matched by proximity (1.52 km)
County Ranking
Ranked #1 of 6 lakes in Passaic County
Nearby Lakes in Passaic County
Frequently asked questions about Green Turtle Lake
Where is Green Turtle Lake?
- Green Turtle Lake is a lake in Passaic County, New Jersey. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Green Turtle Lake?
- Green Turtle Lake in Passaic County, New Jersey has a water quality grade of D (Nutrient-rich). Water clarity: 7.2 ft visibility. Phosphorus: 13.9 µg/L. Chlorophyll-a (algae): 16.1 µg/L. Surface area: 28 acres.
Is Green Turtle Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Green Turtle Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 16.1 µg/L. Always check local health department advisories before swimming.
Explore Green Turtle Lake across LakeGrade
More New Jersey Lake Rankings
Other Grade D Lakes in New Jersey
Eutrophic Lakes in New Jersey
Where this data comes from
18 measurements from 1 monitoring station, 2021–2024. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- NJDEP Bureau of Freshwater and Biological Monitoring
NJDEP_BFBM18 samples · 2021–2024
Analytical methods
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 2120 B ~ Color in Water by Visual Comparison
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database